Substituted piperazine carbamates

Abstract

Novel substituted piperazine carbamates, pharmaceutical compositions comprising them and use thereof in the treatment and/or prevention of diseases and disorders related to hormone sensitive lipase. More particularly, the compounds are useful for the treatment and/or prevention of diseases and disorders in which modulation of the activity of hormone sensitive lipase is beneficial.

1 . A compound of formula (I):  
     
       
         
         
             
             
         
       
     
     wherein 
 R 1  and R 2  are independently selected from hydrogen, hydroxy, sulfanyl, amino, halogen, sulfo, C 1-6 -alkyl, C 1-6 alkoxy, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, sulfo, C 1-6 -alkyl, C 1-6 -alkoxy, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl may optionally be substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, perhalomethyl, perhalomethoxy, C 1-6 -alkyl, C 1-6 -alkoxy, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl, and C 3-10 -cycloalkyl;  
 X is N or CR 3 ;  
 Y is N or CR 4 ;  
 Z is N or CR 5 ; 
 provided that X, Y and Z are not all CH;  
 
 R 3 , R 4  and R 5  are independently selected from hydrogen, hydroxy, sulfanyl, fluor, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, C 1-6 -alkyl, perhalomethyl and perhalomethoxy;  
 A is selected from CH 2  and CH 2 CH 2 ;  
 R 6  is selected from C 2-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of C 2-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, C 1-6 -alkyl, perhalomethyl and perhalomethoxy;  
 with the proviso that said compound is not 4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester,  
 4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-phenyl ester,  
 4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(2-cyclohexyl-acetylamino)-phenyl ester,  
 4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester,  
 4-(2-Pyridin-4-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(2-Thienylethyl)piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)phenyl ester,  
 4-(Tetrahydrofuran-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(Tetrahydro-furan-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethylphenoxy)-phenyl ester,  
 4-(Tetrahydrofuran-2-ylmethyl)-piperazine-1-carboxylic acid 4-(3-chloro-5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(Tetrahydro-furan-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(4-chloro-phenyl)-ethylcarbamoyl]-phenyl ester  
 4-(5-Chloro-thiophen-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(4-Chlorobenzyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(3,4-Methylenedioxy-benzyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Benzyl-piperazine-1-carboxylic acid pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3-bromo-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-bromo-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 5-bromo-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3,4,5-tribromo-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-chloro-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-iodo-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3-(4-methoxy-phenyl)-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3-(2-methoxy-phenyl)-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3-(4-nitro-phenyl)-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3-(2-fluoro-phenyl)-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3-pyridin-2-yl-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-phenylsulfanyl-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 3-thiophen-2-yl-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 5-thiophen-2-yl-pyrazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-chloro-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-bromo-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-iodo-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-methyl-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-phenylsulfanyl-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-(4-methoxy-phenyl)-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-(4-fluoro-phenyl)-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-thiophen-2-yl-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2-pyridin-2-yl-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 2,5-dichloro-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-bromo-2,5-dichloro-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-bromo-2-chloro-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 5-(4-methoxy-phenyl)-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 5-(4-fluoro-phenyl)-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 5-thiophen-2-yl-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 5-pyridin-2-yl-imidazol-1-yl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester,  
 4-(4-tert-Butylbenzyl)piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)phenyl ester,  
 4-(4-Fluorobenzyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(4-Chlorobenzyl)piperazine-1-carboxylic acid 4-(4-trifluoromethylphenoxy)phenyl ester,  
 4-(4-Methylbenzyl)piperazine-1-carboxylic acid 4-(4-trifluoromethylphenoxy)phenyl ester,  
 4-(4-Methoxybenzyl)piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(2-Chloro-6-fluoro-benzyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-(3-chloro-5-trifluoromethyl-pyridin-2-yloxy)phenyl ester,  
 4-Benzyl-piperazine-1-carboxylic acid 4-iodo-pyrazol-1-yl ester,  
 4-(4-Fluoro-benzyl)-piperazine-1-carboxylic acid 4-iodo-pyrazol-1-yl ester,  
 4-Naphthalen-1-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester  
 4-(3,4-Dichloro-benzyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(3-Methoxy-benzyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(3-Fluoro-benzyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(3-Fluorobenzyl)-piperazine-1-carboxylic acid 4-(4,6-dimethyl-pyrimidin-2-ylsulfanyl)-phenyl ester,  
 4-(4-Methoxy-benzyl)-piperazine-1-carboxylic acid 4-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-phenyl ester,  
 4-(4-Methoxy-benzyl)-piperazine-1-carboxylic acid 4-(2-cyclohexyl-acetylamino)-phenyl ester,  
 4-(4-Methoxy-benzyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester,  
 4-Cyclopropylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Phenethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(3-Phenylpropyl)piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(4-Phenylbutyl)piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(4-Phenylbutyl)piperazine-1-carboxylic acid 4-chlorophenyl ester,  
 4-Cyclopropylmethyl-piperazine-1-carboxylic acid 4-(3-chloro-5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Cyclohexylmethyl-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-phenoxy)-phenyl ester,  
 4-Cyclohexylmethyl-piperazine-1-carboxylic acid 4-(3-chloro-5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Cyclopropylmethyl-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-phenoxy)-phenyl ester,  
 4-(2-Cyclohexyl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Cyclopropylmethyl-piperazine-1-carboxylic acid 4-[2-(4-chloro-phenyl)-ethylcarbamoyl]-phenyl ester,  
 4-Cyclopropylmethyl-piperazine-1-carboxylic acid 4-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-phenyl ester,  
 4-Cyclopropylmethyl-piperazine-1-carboxylic acid 4-(2-cyclohexyl-acetylamino)-phenyl ester,  
 4-Cyclopropylmethyl-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester,  
 4-(2-Hydroxyethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(Pyrrolidinocarbonylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(Isopropylaminocarbonylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Ethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Propyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Butyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(3-Hydroxypropyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-(2-(2-Hydroxyethoxy)ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-[2-(2-Hydroxyethoxy)ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-Octylpiperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)phenyl ester,  
 4-(3-Dimethylamino-propyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,  
 4-[2-(2-Hydroxyethoxy)ethyl]piperazine-1-carboxylic acid 4-(4-trifluoromethylphenoxy)phenyl ester, or  
 4-(1-Methyl-piperidin-4-ylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester; 
 as well as any diastereomer or enantiomer or tautomeric form thereof, mixtures of these, or pharmaceutically acceptable salts thereof.  
 
 
   
   
       2 . A compound according to  claim 1 , wherein R 3 , R 4  and R 5  are independently selected from hydrogen, hydroxy, sulfanyl, fluor, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, C 1-6 -alkyl, perhalomethyl and perhalomethoxy.  
   
   
       3 . A compound according to  claim 1 , wherein R 6  is selected from aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, C 1-6 -alkyl, perhalomethyl and perhalomethoxy.  
   
   
       4 . A compound according to  claim 1 , wherein R 6  is an aryl which is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-10 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, C 1-6 -alkyl, perhalomethyl and perhalomethoxy.  
   
   
       5 . A compound according to  claim 4 , wherein R 6  is a phenyl which is optionally substituted.  
   
   
       6 . A compound according to  claim 4 , wherein R 6  is a pyridyl which is optionally substituted.  
   
   
       7 . A compound according to  claim 1 , wherein 
 R 6  is selected from:                          
   
   
       8 . A compound according to  claim 1 , wherein 
 R 1  and R 2  are hydrogen;    X is N or CR 3 , Y is N or CR 4 , Z is N or CR 5 ; provided that X, Y and Z are not all CH; and    R 6  is selected from:                          
   
   
       9 . A compound according to  claim 1 , wherein 
 R 1  and R 2  are hydrogen;    X is CR 3 ;    Y is C—H;    Z is N or CH; and    R 6  is selected from:                          
   
   
       10 . A compound according to  claim 1 , wherein 
 R 1  and R 2  are hydrogen;    X is CR 3 ;    Y and Z are each CH;    R 6  is selected from:                          
   
   
       11 . A compound according to  claim 1 , wherein 
 R 1  and R 2  are hydrogen;    X is CR 3 ;    Y and Z are each CH;    R 6  is selected from:                          R 3  are independently selected from hydroxy, amino, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, amino, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, C 1-6 -alkyl, perhalomethyl and perhalomethoxy.    
   
   
       12 . A compound according to  claim 11 , wherein 
 R 3  are independently selected from hydroxy, amino, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, amino, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl, wherein each of hydroxy, sulfanyl, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl is optionally substituted with one or more substituents independently selected from hydroxy, sulfanyl, oxo, halogen, amino, sulfo, C 1-6 -alkyl, C 2-6 -alkenyl, aryl, heteroaryl, C 3-8 -heterocyclyl and C 3-10 -cycloalkyl.    
   
   
       13 . A compound according to  claim 1 , wherein A is CH 2 CH 2 .  
   
   
       14 . A compound according to  claim 1 , wherein A is CH 2 .  
   
   
       15 . A compound according to  claim 1 , wherein R 1  is hydrogen.  
   
   
       16 . A compound according to  claim 1 , wherein R 2  is hydrogen.  
   
   
       17 . A compound according to  claim 1 , wherein R 1  is hydrogen and R 2  is hydrogen.  
   
   
       18 . A compound according to  claim 1 , wherein R 2  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       19 . A compound according to  claim 1 , wherein R 2  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       20 . A compound according to  claim 1 , wherein R 2  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       21 . A compound according to  claim 1 , wherein R 2  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       22 . A compound according to  claim 1 , wherein X is N.  
   
   
       23 . A compound according to  claim 1 , wherein X is CH.  
   
   
       24 . A compound according to  claim 1 , wherein X is C—R 3 .  
   
   
       25 . A compound according to  claim 1 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       26 . A compound according to  claim 1 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       27 . A compound according to  claim 1 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       28 . A compound according to  claim 1 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       29 . A compound according to  claim 1 , wherein Z is N.  
   
   
       30 . A compound according to  claim 1 , wherein Z is C—R 5 .  
   
   
       31 . A compound according to  claim 1 , wherein Z is CH.  
   
   
       32 . A compound according to  claim 1 , wherein Y is N.  
   
   
       33 . A compound according to  claim 1 , wherein Y is CH.  
   
   
       34 . A compound according to  claim 1 , wherein Y is C—R 4 .  
   
   
       35 . A compound according to  claim 1 , wherein only one of X, Y and Z is N.  
   
   
       36 . A compound according to  claim 1 , wherein X is C—R 3 , Y is C—R 4  and Z is C—R 5 .  
   
   
       37 . A compound according to  claim 1 , wherein Y and Z are both CH.  
   
   
       38 . A compound according to  claim 37 , wherein X is C—R 3 .  
   
   
       39 . A compound according to  claim 38 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       40 . A compound according to  claim 38 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       41 . A compound according to  claim 38 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       42 . A compound according to  claim 38 , wherein R 3  is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
       60 . A compound according to  claim 1 , where the compound is selected from the group consisting of 
 4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester,    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester,    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester,    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester,    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester,    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester,    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester,    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester,    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester, and    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester.    
   
   
       43 . A compound according to  claim 1 , where the compound is selected from the group consisting of: 
 4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-yloxy)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-chloro-pyridin-2-yloxy)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3,3-dimethyl-butylcarbamoyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-trifluoromethyl-benzyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4,4-dimethyl-2,6-dioxo-3,4,5,6-tetrahydro-2H-[1,3′]bipyridinyl-6′-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-benzoylamino-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-(3-tert-butyl-thioureido)-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-benzoylamino-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-(1,3-dioxo-octahydro-isoindol-2-yl)-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid quinolin-7-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid quinolin-7-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid quinolin-7-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid quinolin-7-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid quinolin-7-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid quinolin-7-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid quinolin-7-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid quinolin-7-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1,1,3,3-tetramethyl-butylcarbamoyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(cyclohexanecarbonyl-amino)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4,4-dimethyl-2,6-dioxo-piperidin-1-yl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(6-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(1H-imidazol-2-ylsulfanylmethyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-isopropyl-5-oxo-2-thioxo-imidazolidin-1-yl)-pyridin-3-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-morpholin-4-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-morpholin-4-ylmethyl-benzoylamino)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 6-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-3-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-piperidin-1-ylmethyl-benzoylamino)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-(4-piperidin-1-ylmethyl-benzoylamino)-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester 4-[2-(1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-ethyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(4-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(3-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 5-[4-(2-methyl-piperidin-1-ylmethyl)-benzoylamino]-pyridin-2-yl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(5-trifluoromethyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-yl methyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(4-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-pyridin-2-ylmethyl-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-(3-methyl-pyridin-2-ylmethyl)-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(1-methyl-1H-imidazol-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-ylsulfanyl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-2-yloxy)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-3-yloxy)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(pyridin-4-yloxy)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(6-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(4-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(3-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Pyridin-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrimidin-4-ylmethyl-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyrazin-2-ylmethyl-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(6-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(6-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Pyridin-3-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-3-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(3-Pyridin-2-yl-propyl)-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(6-Methyl-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-Pyridin-3-ylmethyl-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(4-Methyl-thiazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Carboxy-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(5-Carboxy-pyridin-2-ylmethyl)-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(5-Methyl-pyridin-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[3-(5-Methyl-pyridin-2-yl)-propyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-(2-Thiazol-2-yl-ethyl)-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(2-Methyl-thiazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Pyrrol-2-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1H-Imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester    4-[2-(1-Methyl-1H-imidazol-4-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester, and    4-[2-(3-Methyl-isoxazol-5-yl)-ethyl]-piperazine-1-carboxylic acid 4-[2-(5-methyl-pyridin-2-yl)-ethyl]-phenyl ester.    
   
   
       44 . A pharmaceutical composition comprising a compound according to  claim 1 , or a pharmaceutically acceptable salt thereof together with a pharmaceutically acceptable carrier or diluent.  
   
   
       45 . The composition according to  claim 44 , wherein said composition is in unit dosage form, comprising from about 0.05 to about 2000 mg, from about 0.1 to about 500 mg, or from about 1.0 to about 100 mg of said compound according to  claim 1 , or pharmaceutically acceptable salt thereof.  
   
   
       46 . A pharmaceutical composition for use as a medicament for inhibiting the lipolytic activity of hormone-sensitive lipase against triacylglycerols, diacylglycerols, cholesterol acyl esters or steroid acyl esters, said composition comprising a compound according to  claim 1 , or a pharmaceutically acceptable salt thereof together with a pharmaceutically acceptable carrier or diluent.  
   
   
       47 . A pharmaceutical composition according to  claim 44 , which is for oral administration.  
   
   
       48 . A pharmaceutical composition according to  claim 44 , for nasal, transdermal, pulmonal, or parenteral administration.  
   
   
       49 . A method of treating a disorder of a patient where modulation of the activity of hormone-sensitive lipase is desired, the method comprising administering to a subject in need thereof a therapeutically effective amount of a compound according to  claim 1 , or a pharmaceutically acceptable salt thereof.  
   
   
       50 . A method of treating a disorder of a patient where lowering of the activity of hormone-sensitive lipase is desired, the method comprising administering to a subject in need thereof a therapeutically effective amount of a compound according to  claim 1 , or a pharmaceutically acceptable salt thereof.  
   
   
       51 . The method according to  claim 49 , wherein said administration is carried out by the oral, nasal, transdermal, pulmonal, or parenteral route.  
   
   
       52 . The method according to  claim 49 , wherein said disorder is selected from the group consisting of insulin resistance, diabetes type 1, diabetes type 2, metabolic syndrome X, impaired glucose tolerance, hyperglycemia, dyslipidemia, obesity, atheroschlerosis, hypertension, abnormalities of lipoprotein metabolism and any combination thereof.  
   
   
       53 . The method according to  claim 49 , wherein the therapeutically effective amount of the compound is from about 0.05 to about 2000 mg, from about 0.1 to about 500 mg, or from about 1.0 to about 100 mg of said compound per day.  
   
   
       54 . The method according to  claim 49 , wherein a further antidiabetic, antiobesity, antihypertensive or appetite regulating drug is administered to the patient.  
   
   
       55 . The method according to  claim 49 , wherein metformin is also administered to the patient.  
   
   
       56 . A process for the preparation of a compound according to  claim 1 , or its pharmaceutically acceptable salt, which comprises reacting the appropriate phenol with the appropriate carbamoylating reagent in a solvent according to the reaction scheme P 1   
     
       
         
         
             
             
         
       
     
     and isolating the disubstituted carbamate product.  
   
   
       57 . The process according to  claim 56 , wherein said carbamoylating reagent  
     
       
         
         
             
             
         
       
     
     is selected from the group consisting of  
     
       
         
         
             
             
         
       
     
   
   
       58 . The process according to  claim 56 , wherein said solvent is selected from the group consisting of tetrahydrofurane, dimethylformamide and N-methylpyrolidone.  
   
   
       59 . The process according to  claim 56 , wherein said base is selected from the group consisting of triethylamine, N,N-diisopropyl-N-ethylamine and DABCO.  
   
   
       60 . A process for the preparation of a compound according to  claim 1 , said process comprising the treatment of the appropriate amine with the appropriate acylating reagent in a solvent according to the reaction scheme P 2   
     
       
         
         
             
             
         
       
     
     wherein Lv is a leaving group, and isolating the disubstituted carbamate as a salt with the acid H-Lv.  
   
   
       61 . The process according to  claim 60 , wherein Lv is Cl.  
   
   
       62 . The process according to  claim 60 , wherein said solvent is selected from the group consisting of diethyl ether, tetrahydrofuran and dichloromethane.  
   
   
       63 . The process according to  claim 60 , wherein said base is selected from the group consisting of trimethylamine, triethylamine, ethyl-diisopropyl-amine and 1,4-diazabicyclo[2.2.2]octane.